Reversing valve



April 4, 1944. J. E. WHITFIELD REVERS ING VALVE Filed Jan. 18, 1943 4 Sheets-Sheet I VENTOR.

April 4, 1944. J. E. WHITFIELD REVERS ING VALVE Y '4 Sheets-Sheet 2 Filed Jan. 18, 1945 effe/00M Y x x 2 J L :Fin l April 4, 1944.

J.' E. WHITFIELD REVERS ING VALVE Filed Jan. 18, 1945 4 Sheets-Sheetl 5 IN VENTOR.

A'pril 4, 1944. J. E. WHITFIELD REVERS ING VALVE Filed Jan. 18, 1945 4 Sheets-Sheet 4 1N VENTOR Patented Apr. 4, 1944 UNITED STATES PATENT OFFICE REVERSING VALVE Joseph E. Whiteld, Hamilton, Ohio Application January 18, 1943, Serial No. 472,659

6 Claims.

This invention relates generally to reversing* valves and more particularly to reversing valves for changing the direction of flow of scavenging or supercharging air produced by a screw blower driven directly from the shaft of a reversible marine Diesel engine.

The screw olower is shown and described in Letters Patent No. 2,287,716 and is made up of a rotor member and a gate member disposed ln parallelism and having complementary intermeshing helical threads, the curved sides of the rotor threads being described by the continuous edges of the helical threads of the gate, and the curved troughs of the gate being described by the continuous edges of the crests of the helical threads of the rotor. This is an axial ilow blower that produces the same now characteristics when rotated in either direction and is effective in producing the air ow required commensurate with the speed of the engine. 'I'he valve for switching the port connection must be reversed after su-fllcient air has been supplied to scavenge the cylinders before the engine stops and before it is started in the reverse direction. It is therefore necessary to actuate the reversing valve in timed relation with the reversal of the engine.

The principal object of this invention is the provision of a reversing valve for changing the direction of the ilow of scavenging air from a screw blower to a reversible internal combustion engine.

Another object is the provision of an air flow reversing valve that has a low resistance to the passage of air therethrough.

Another object is the provision of.a unitary reversing valve made in one piece and having relatively small space requirements.

Another object is the provision of a reversing valve that is simple in construction and economical to manufacture.

Another object is the provision of a reversing valve having a continuous cylindrical sealing line the intermediate portion of which is circular and the remote ends follow the curve formed by the intersection of two intersecting cylinders with their axes disposed normal to one another.

Another object is the provision of a reversing valve having a continuous sealing line inscribed in a cylindrical surface with opposite intermediate portions in the same transverse plane which are connected at their adjacent ends by opposltely disposed concave arcuate portions.

Another object is the provision of a reversing ous sealing line inscribed in a cylindrical surface following the intersection of two parallel planes connected byan intermediate plane radial to the cylindrical surface.

Another object is the provision of a reversing valve member having oppositely extending gudgeons the outer ends of which are axially aligned for rotatably carrying the valve.

Other objects and advantages appear in the following description and claims.

In the accompanying drawings a practical embodiment illustrating the principles of this invention is shown wherein:

Fig. 1 is a vertical sectional view of the reversing valve case and valve member comprising this invention.

Fig. 2 is a view similar to Fig. 1 showing the valve member in its reversed position.

Fig. 3 is a schematic view of an internal combastion engine with the blower and reversing valve mounted thereon.

Fig. 4 is a partial sectional view of the valve and casing when observed from the intake port.

Fig. 5 is a sectional view taken on the line I- of Fig. 4.

b Fig. 6 is a perspective view of the valve mem- Fig. 'I is a sectional view taken on the line 1--1 of Fig. 5.

Fig. 8 is a sectional view showing the valve as in Fig. 4 tosether with rotor members of a screw blower.

Fig. 9 is a schematic view of the sealing surfaces of the valve case shown in Figs. l and 2.

Fig. 10 is a schematic view of the sealing surface of the valve shown in Figs. l and 2.

Fig. l1 is a schematic view of the sealing sur` faces of the valve case shown in Figs. 4 and 5.

Fig. 12 is a. schematic view of the sealing surface of the valve shown in Figs. 4 and 5.

Referring to the drawings, I0 represents the valve member made up of oppositely disposed aligned for rotatably supporting the valve member. The lower gudgeon Il is provided with a radial shoulder i3 that engages the end of the bearing Il and forms the rotary part of a collar thrust bearing. The bearing I4 has a radial ange at the lower end thereof whlchis arranged to be bolted to the seat produced by the enlarged bore in the under face that closes the botvalve having a symmetrically balanced continutom of the valve casing I5. A cap plate is bolted to the underside of thebearing flange for enclosing the gudgeon in the bore. .i

The upper gudgeon I2 is journaled in a bearing formed in the circular plate I6 that closes the upper end of the valve casing I5. The gudgeon I2 extends through the closure plate I6 and is arranged to be connected to a suitable servo motor for actuating the valve member. In Fig. 3 a hand lever I1 has been provided in place of the servo motor, for the purpose of illustrating means for rotating the valve. The upper end of the gudgeon I2 is provided with a coupling to facilitate the assemblyhof the valve to the servo motor.

The valve casing l5 has a cylindrical bore or valve chamber I8 the rear side of which opens directly into an upper and lower blower port 20 and 2| divided by the horizontal central partition 22. The valve chamber I8 thus forms an aperture in the transverse partition wall 22. The front of the valve casing I5, which is removed in Figs. 1 and 2, is cylindrical as indicated in Fig. 3.

Aligned lateral ports 23 and 24 are formed in the sides of the valve casing I5 and are connected by passageways to the intake muffler 25 and the discharge header 26 respectively. The ports 23 and 24 are circular in cross section and they intersect and interrupt the cylindrical bore or aperture I8 of the valve casing with their axes normal to the axis of the latter.

The internal combustion engine 21 shown in Fig. 3 has the axial now screw blower 28 mounted on the end thereof. The rotor member of the screw blower is larger in diameter than the gate member and is directly connected to the engine. The overall diameters of the rotor and gate respectively are similar to the outline of the blower casing as shown. A set of timing gears connect the shafts of the rotor and gate members to keep them rotating in timed relation and thus avoid the necessity of driving the gate by the intermeshing threads of the members. The horizontal partition Wall 22 which divides the upper and lower blower ports 20 and 2l is shown in Fig. 3. The port 20 is connected `to the passageway that extends up around to the left side of the blower adjacent the rear thereof, while the port 2l is connected to the passageway leading to the right side of the blower adjacent the front thereof. Since this blower is designed to have the same flow characteristics in either direction the front and rear ports connected, to the blower chamber should be equivalent in shape and size.

In the valve chamber or aperture It the horizontal partition wall 22 and a corresponding portion of the opposite cylindrical wall are raised from the bore as indicated at 3E. These arcuate surfaces provide the horizontal sections of the valve sealing line. The rest of the valve sealing line is formed by the raised portions 3| and 32 which follow the curves produced by the intersection of the cylindrical ports 23 and 24, respectively, withthe cylindrical valve chamber I8 and which encircle said ports. Thus the raised surfaces 30, 3I and 32 which are joined together form a continuous sealingline lying in an inner cylindrical surface concentrically disposed within the valve chamber.

The valve member Ill has a lateral sealing surface 33 which corresponds to the horizontal sealing surfaces 30 and the arched or outer edges of the hoods correspond to one-half of the port sealing surfaces as indicated at 34 and 35. These asimso surfaces are integrally joined together, thus forming a continuous sealing surface for the full circumference of the valve member Ill.

AWhen the valve is positioned as shown in Fig. 1 its arcuate sealing surface 34 mates with the upper half of the valve chamber sealing surface 3I that encircles the port 23, and its arcuate sealing surface 35 mates with the lower half of the valve chamber sealing surface 32 that encircles the port 2d. When the valve member lll is rotated through 180 its arcuate seal- I ing surface 35 mates with the lower half of the valve chamber sealing surface 3l that encircles the port 23, and its arcuate sealing surface 34 mates with the upper half of the valve chamber' sealing surface 32 that encircles the port 24 as shown in Fig. 2. In either position the horizontal sealing surfaces 33 on each side of the valve member mate with the corresponding seal ing surfaces 30 in the valve chamber.

If the valve member were constructed by using three flat plates corresponding to the three transverse planes passing through the sealing lines 3d, 30 and 35, like the risers and tread of a step, the port openings would be greatly restricted. Again if a single at web were used which extended diagonally from tip to tip of the valve, the port, openings would still be partially restricted. To avoid these disadvantages the face of the web of the valve member adjacent the ports is formed concave in the shape of a hood or bonnet, thereby providing an unrestricted uid passage. The back of the concave surface is con.. vex and provides a materially strengthened structure for securing the gudgeons Ii and l2 thereto. When the gudgeons join the convex hood portion of the web they .are attened as indicated at 3B and shaped into an air flow surface. The gudgeons could be changed to a shaft but the latter structure would not be as mechanically strong as the former.

A suitable stop such as that indicated by the posts 3l and 38 may be provided with the valve operating'means for aligning the mating sealing surface in the two positions apart. f

A. modifled form of the valve and casing is shown in Figs. 4, 5 and '7 and the valve member alone is shown in the perspective view` of Fig. 6. in Figs. fi, 5 and 7 the valve casing I 5 is also formed integral with the screw blower housing and the gudgeons II and I2 which rotatably support the valve in the casing are altered somewhat in their shape. The thrust bearing I3 at the lower end of the gudgeon II is proportionately larger to support the heavy load due to the pneumatic pressure on the valve when posisioned as shown. The complementary bearing It is provided with an upper flange the top of which forms thecounterpart of the thrust bearing I3 and the under side rests on the boss formed in the casting. A ring dll is secured to the lower end of the bearing Iii by the bolts 4I and is arranged to engage the under side of the boss in the casting I5 to hold the bearing in place. A plate d2 covering the ring 40 is bolted to the bottom of the gudgeon II to enclose the bearing and hold the valve in its proper `position when the pneumatic pressure is directed against the under side of the valve tending to lift lt.

The upper gudgeon I2 has a radially disposed ange t3 formed integral therewith which ts into a downwardly open socket in the disk di that is secured to the lower end of the servo motor shaft 45. The structure of the servo motor d6 forms the subject matter of a cao-pending disclosure. However the bearing of the servo motor shaft serves as the upper valve bearing for the gudgeon I2. A friction plunger 4'| bears against flattened sections 48 on the edge of the disk 44 and thus braces the Vvalve against a pulsating pneumatic pressure that tends to vibrate the valve.

The partition 22 is disposed horizontally in the vicinity of the valve member as shown in Figs. 4 and 5 to carry the horizontal sealing surfaces 30 of the valve casing. As the partition 22 extends toward the blower unit it divides the valve casing diagonally to direct the upper blower port 20 to the left in Fig. 5 and the lower blower port 2| to the right. The passageway leading from the upper port 2|) extends to the opposite side of the rotor members and to the front while the passageway leading from the lower blower port 2| goes to the near side of the rotor members and to the rear.

It will be noted that the horizontal or lateral sealing surfaces 3D are somewhat longer in Fig. 5 than that shown in Figs. 1 and 2 due to the shape of the inlet and outlet ports 23 and 24. These ports are defined by the valve casing sealing surfaces 3| and 32 which in Figs. l and 2 are constructed by the intersection of two cylindrical surfaces the axes of which are normal to each other. In Figs. 4 and 5 the ports 23 and 24 are oblong in shape with straight sides and curved ends and defined by the sealing surfaces 3| and 32 having the same shape and lying in a common cylindrical plane. This oblong port provides a particular advantage in theair flow characteristics of the valve and is an important object of this invention.

If a piece of paper was mounted on a platen and rolled around against the continuous sealing surfaces 3U, 3| and 32 in the valve casing to obtain an impression thereof and then flattened out, these sealing surfaces would appear as shown in Figs. 9 and 1l. The valve sealing surfaces of Fig. 9 are taken from the valve casing shown in Figs. 1 and 2 and the valve sealing surfaces of Fig. 11 are taken from the valve casing shown in Figs. 4 and 5. The schematic views of Figs. 9 and 11 demonstrate how vastly different characters of valve openings may be obtained with relatively small changes in the shape of the hoods or bonnets of the valve member.

The lateral sealing surfaces 33, and the outer arcuate sealing surfaces 34 and 35 of the valve member hoods mate with the corresponding sealing surfaces of the case and also lie in a common cylindrical surface. The upper bonnet or hood section of the valve member carrying the U-shaped sealing surface 34 mates with the upper portion ofthe sealing surfaces 3| and 32 and the sealing surface 35 of the lower bonnet or hood section mates with the lower portion of the same sealing surfaces. The oblong ports requiring a mating counterpart of the valve member produce an open throat for the free flow of fluid therethrough. The gudgeons have a streamline surface and offer very little resistance. The position of the valvein Figs. 4 and 5 directs the flow from the intake to the lower port 2| where it is directed to the rear end of the blower and is forced from the front end through the port 20 and is thence directed by the valve member to the discharge port 24.

The valve member I0 shown in Fig'. 6 clearly of the valve member, which surfaces lie in a common cylindrical surface.

If the continuous sealing surface of the valve members of Figs. 1 and 4 were painted and then rolled over a piece of paper they would leave the impressions indicated in the schematic views of Figs. 10 and 12 respectively which correspond to their mating sealing surfaces of the valve casings as shown in Figs. 9 and 11. If the seal ing surfaces 33, 34 and 35 of the valve members were superimposed on their corresponding sealing surfaces 30, 3| and 32 of the valve casing and were moved back and forth to alternately register with the inlet and outlet openings 23 and 24 the action would simulate the movement of the valve in the casing through The sectional view shown in Fig. 8 illustrates the relative positions of the valve I0 and the screw blower 28. The screw blower comprises the casing 50 which is formed integral with the valve casing I5 and .encloses the upper and lower blower parts 2|) and 2| respectively. IThe upper blower port 20 extends around the top of the gate member 5| to the juncture between the gate member 5| and the rotor member These rotary members operate within cylindrical chambers 53 and 54, respectively, which intersect to form a common blower chamber that permits the gate and rotor members to intermesh with one another. The blower port 20 term minates at the port 55 of the blower chamber and the blower port 2| terminates at the port 56 in the blower chamber. The port 55 extends to and uncovers a part of the front end of the rotary members 5| and 52 and the port 56 extends to and uncovers part of the rear of the rotary members. Timing gears, which are not shown, are employed to maintain the gate and the rotor members in their proper meshed relan "tion and by driving the shaft of the rotor member in either direction pockets are formed be tween these rotary members and the blower chamber, which pockets convey the air or fluid from one blower chamber port to the other.

Although practical embodiments illustrating the principles of this valve have been shown and described in conjunction with a screw blower which provides scavenging air for Diesel engines it is obviously applicable as a reversing valve for controlling the flow of uids in other installations.

I claim:

l. A valve comprising a body forming a housing, a transverse partition dividing the housing into inlet and outlet chambers and having an aperture therethrough, a port in each of the opposite walls of the housing which interrupts the edge of the aperture, the surfaces defining the aperture and both ports being joined together and located in a common surface of revolution about an axis normal to the partition, a valve member in the hous ing supported for rotation about said axis, said valve member having an intermediate base portion the outer arcuate surfaces of which register with the uninterrupted portions of said aperture and oppositely disposed hoods, one hood extending.

from the upper and the other from the lower side of thev base portion, the outer edge of each hood registering with only one-half of its associated port to selectively connect either port to the inlet and outlet chambers when the valve is in opera tive position.

2. The structure of claim 1 in which the surraces defining the aperture and both ports are valve member having oppositely disposed arched hoods on opposite sides of a common transverse plane in which their lateral edges and back walls are integrally joined together, the lateral and outer arcuate edges of each hood registering with the uninterrupted portions o said aperture and one-half o the associated ports respectively to selectively connect either port to the inlet and assays@ outlet chambers when the valve` is in operative position.

4. The structure of claim 3 characterized in that the outer arcuate edges o the hoods and the corresponding port surfaces are semicircular.

5. The structure of claims characterized in that the outer arcuate edges of the hoods and the corresponding port surfaces are oblong.

6. A rotary valve member of the character disclosed comprising oppositeiy disposed arched hoods which lie on opposite sides oi a common transverse plane in which the lateral edges and back walls of the hoods are integrally joined together, stem means connected to said hoods for rotatably supporting and tg the valve mem ber, the surfaces defining the lateral and outer arched edges of both hoods being continuous and located in a coon surface of revolution about the rotary axis of the valve member.

JOSEPH E. i 

